The present invention broadly relates to a detection apparatus for printed products or the like and more specifically, pertains to a new and improved construction of an apparatus for detecting multiple occupied positions in a continuously conveyed flow or stream of printed products arranged at uniform spacing with respect to one another. The present invention also pertains to a method of using such apparatus.
Generally speaking, the apparatus for detecting multiple occupied positions in a sequential or successive flow or stream of products continuously conveyed at uniform spacing comprises a deflectable sensor element oriented substantially toward a first or one side of the stream of printed products, a counter-element oriented substantially toward a second or other side of the stream of printed products and arranged in essentially opposing relation to the sensor element, wherein the second lower side of the stream of printed products is opposite the first upper side thereof.
An apparatus of this type is known, for instance, from the Swiss Pat. No. 523,787, granted June 15, 1972. In this apparatus, the sensor or feeling element is a wheel bearing continuously upon the transported printed products and journalled upon the end of a shaft which is, in turn, pivotable in a direction transverse to its longitudinal extent. The degree of pivoting of this shaft forms a measure of the thickness of the printed products conveyed beneath the wheel. The degree of pivoting of this shaft is, also, only sensed at predetermined times governed by the prescribed or reference sequential rate of flow of the printed products. This known apparatus is therefore in principle able to detect not only a multiple occupied position in the flow or stream of printed products but also an unoccupied position. A principal disadvantage of this known apparatus, however, is that the wheel rolls continuously upon the conveyed printed products and thereby exerts a mechanical pressure thereupon which leaves traces upon the printed products even when the wheel is synchronously driven.